1316891521 has 9 divisors (see below), whose sum is σ = 1447931233. Its totient is φ = 1196811220.

The previous prime is 1316891509. The next prime is 1316891549. The reversal of 1316891521 is 1251986131.

The square root of 1316891521 is 36289.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1316891521 - 2⁷ = 1316891393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1316891551) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 397530 + ... + 400828.

Almost surely, 2^1316891521 is an apocalyptic number.

1316891521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1316891521 is the 36289-th square number.

1316891521 is the 18145-th centered octagonal number.

It is an amenable number.

1316891521 is a deficient number, since it is larger than the sum of its proper divisors (131039712).

1316891521 is an frugal number, since it uses more digits than its factorization.

1316891521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6620 (or 3310 counting only the distinct ones).

The product of its digits is 12960, while the sum is 37.

The cubic root of 1316891521 is about 1096.0995525680.

The spelling of 1316891521 in words is "one billion, three hundred sixteen million, eight hundred ninety-one thousand, five hundred twenty-one".